Cops are investigating a break-in at the Coney Island Best Buy where thieves made off with $75,000 in electronics. Photo: Paul Martinka

Crafty crooks busted a hole in the backside of a waterfront Best Buy in Coney Island — then fled with fancy electronics, pulling off a $75,000 heist, law enforcement sources said on Tuesday.

An officer enters the 62nd precinct lugging the ladder police believe was used in the heist. Also found were a huge crowbar and sledgehammer.Photo: Paul Martinka

The thieves used a jackhammer to smash the four-foot-tall hole before snatching iPads and global positioning devices then fleeing through an alley next to the shop on Bay Parkway and Bay View Place, early Tuesday, law enforcement sources said.

Cops discovered a snipped chain-link fence leading to the alley and spotted “drag marks” on the cement nearby.

Police first thought the crooks had used a boat to enter the shop because a ladder was found in a canal next to the store — but that theory hasn’t held up, law enforcement sources said.

The burglary may be linked to a string of Best Buy thefts, law enforcement sources said.